Structural sensing is mandatory during the development of high performance materials such as
advanced hybrid aluminum composites; moreover, users such as aircraft manufacturers
increasingly seek to implement lifetime structural health monitoring of their products. However,
transducer attachment and wiring represent significant limitations, often prohibitive, to structural
sensing and structural health monitoring. The proposed project will revolutionize the technology
for aluminum products by depositing onto the structural panel a thin film of aluminum nitride, a
piezoelectric material suitable for structural sensing, followed by a thin-film surface electrode and interconnect layer. That is, the structural sensors and their conductors will be integrated with the aluminum material. Other researchers have shown that aluminum nitride thin films can be
deposited on various substrates, in some cases to construct acoustic wave devices, but our
project will be the first to do so for aluminum alloy products such as used in aircraft manufacture.
In this project we will construct a small portable apparatus for sputter deposition on large flat
panels, we will develop the process for reactive sputtering of the aluminum nitride transducer
material on aluminum alloy panels, and we will characterize the piezoelectric material properties.